1. Field
This disclosure relates to a negative active material for a rechargeable lithium battery, a method of manufacturing the same, and a rechargeable lithium battery including the same.
2. Description of the Related Art
Batteries generate electric power using electrochemical reaction materials (referred to hereinafter simply as an “active material”) for a positive electrode and a negative electrode. Lithium rechargeable batteries generate electrical energy from changes of chemical potential during the intercalation/deintercalation of lithium ions at the positive and negative electrodes.
Lithium rechargeable batteries use materials that reversibly intercalate or deintercalate lithium ions during charge and discharge reactions for both positive and negative active materials, and contain an organic electrolyte or a polymer electrolyte between the positive electrode and the negative electrode.
For a positive active material for a rechargeable lithium battery, composite metal oxides such as LiCoO2, LiMn2O4, LiNiO2, LiNi1-xCoxO2 (0<x<1), LiMnO2, and the like have been researched.
For a negative active material of a rechargeable lithium battery, various carbon-based materials such as artificial graphite, natural graphite, and hard carbon, which can intercalate and deintercalate lithium ions, have been used. Since graphite among the carbon-based materials has a low discharge potential relative to lithium of −0.2V, a battery using the graphite as a negative active material has a high discharge potential ranging from 3.6V and excellent energy density. Furthermore, the graphite guarantees a long cycle life for a battery due to its outstanding reversibility. However, a graphite active material has low density about 1.6 g/cc and consequently low capacity in terms of energy density per unit volume when the graphite is used as a negative active material.
Therefore, recently a high-capacity negative active material that can replace a graphite active material has been researched.